Set some sane limits on the disk cache for people who forget. (#201)

* Set some sane limits on the disk cache for people who forget.

* Add CHANGELOG entry

* let's go with 50 instead

Author: garrettmoon

CHANGELOG.md

@@ -1,6 +1,7 @@
 ## master
 
 * Add your own contributions to the next release on the line below this with your name.
+- [fix] Add some sane limits to the disk cache: [#201]https://github.com/pinterest/PINCache/pull/201
 
 ## 3.0.1 -- Beta 5
 - [fix] Respect small byteLimit settings by checking object size in setObject: [#198](https://github.com/pinterest/PINCache/pull/198)

Source/PINDiskCache.m

@@ -150,8 +150,11 @@ - (instancetype)initWithName:(NSString *)name
         _didRemoveAllObjectsBlock = nil;
 
         _byteCount = 0;
-        _byteLimit = 0;
-        _ageLimit = 0.0;
+        
+        // 50 MB by default
+        _byteLimit = 50 * 1024 * 1024;
+        // 30 days by default
+        _ageLimit = 60 * 60 * 24 * 30;
 
 #if TARGET_OS_IPHONE
         _writingProtectionOption = NSDataWritingFileProtectionNone;